theophylline and St John's wort

Last reviewed 01/2018

St John's wort (SJW) interacts with theophylline and may cause reduced theophylline levels.

Suggested management of patients already taking SJW preparations:

  • check theophylline levels and stop SJW

  • note that there may be an increase in theophylline levels on stopping SJW

  • it may be necessary to adjust the theophylline dose


  • CEM/CMO/2000/4